GoldenEye Spectrum Emulation Unlocked - The RWP Forums: "Little benownst to the world all this time, GoldenEye (N64) has a fully-functional ZX Spectrum 48x emulator built into it. By feeding it a proper Spectrum monitor program and calling menu 25 to load a snapshot, any Spectrum 48x program can be run.
The emulator started life as a side project to see if Spectrum emulation was possible on N64 and was hooked into GE, the current game in development. It was supposed to be removed before release but was only made inaccessible and inoperable. All the registers, dependancies, and script required to run the emulator still reside in retail GoldenEye carts.
'via Blog this'